This proposal is designed to provide the opportunity for the Principal Investigator (PI) to gain knowledge and skills in medical outcomes, economics and cost effectiveness evaluation under the supervision of an advisory committee comprising a highly qualified sponsor and co-investigators. The PI has exceptional clinical training and has completed a two-year fellowship in respiratory epidemiology at the Channing Laboratory. In addition she has obtained an M.S. in Clinical Epidemiology at the Harvard School of Public Health. This award in combination with the PI's background provides an excellent potential for development of a successful independent research career. The overall scientific goal of this proposal is to determine whether individuals with asthma management that conforms with recommendations published within the National Asthma Education and Prevention Program (NAEPP) Guidelines for the Diagnosis and Management of Asthma, results in an improved clinical outcome and is cost effective relative to individuals whose management does not conform. We propose to use the extensive information available on a cohort of adult and pediatric asthma patients assembled at Harvard Pilgrim Health Care (HPHC) in a retrospective cohort study design. We hypothesize that individuals with asthma pharmacotherapy and non- pharmacologic management (outpatient follow-up and specialist referral, asthma education, peak flow utilization, environmental measures) that conforms with the NAEPP Guidelines will have decreased health care utilization, improved Health Related Quality of Life (HRQL) and will be cost effective when compared with individuals whose management does not conform. This proposal is vital to the care of more than 14 million asthmatics in the United States. The NAEPP urges that evaluation of the guidelines be given "high priority," and that evaluation should consider not only evidence of efficacy but effectiveness, costs, and cost effectiveness of the therapeutic recommendations put forth.